FERMENTATION 257 



until all the fibrin separates. Filter through 

 gauze into a cylinder holding 100 c.c. To the 

 30 c.c. defibrinated blood add 30 c.c. sodium 

 chloride solution (0.5 per cent) containing 0.6 

 gram salt-free peptone. The mixture will thus 

 contain 1.0 per cent of peptone. Eeserve 5 c.c. 

 of the mixture. Place the rest in a half-litre 

 flask, provided with a stopper pierced by two 

 glass tubes, one reaching to near the bottom 

 of the flask, the other ending just beneath the 

 stopper so that air may be drawn through the 

 blood-peptone solution by an aspirator. Place 

 the flask in a beaker with a heavy iron ring 

 around the neck to prevent the flask being driven 

 upward, fill the beaker with water at 40 C. and 

 place it in a water bath also at 40. 



Separate the intestine carefully from the mes- 

 entery and especially the pancreas. Slit the 

 intestine from the pylorus to the ilio-csecal valve 

 with scissors, cut it into several pieces, wash it 

 in a large water-bath filled with 0.5 per cent 

 sodium chloride solution at 40 C. Kepeat the 

 washing in a second and a third bath. Cut the 

 intestine into finger-lengths. Collect the pieces 

 on a porcelain sieve, wash them with 1 per cent 

 peptone solution, and then place them in the 

 blood-peptone solution. Draw air through the 

 solution, with every possible care against foam- 



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